If you are thinking about getting into podcasting here is how we did it.
Sure, you can start out with a USB mic plugged directly into your computer and if you have a budget of $0 then that is the way you should go. However, if you are willing to invest about $300, you can take your audio quality way up. Content is always king over quality, so focus on that first. However, I’m a stickler for quality so we spend the $300 right off the bat. We use these products: ZOOM H4N Pro Recorder, Pile Dynamic Mic, pop filter (foamy cover thing), XLR cables (the mics come with 1/4″ cables but the quality is lower than with the XLR cables, the ZOOM recorder takes either), and a XLR Y-Spiter (we have 3 corded mics so we had to put two people on one channel). The ZOOM H4N advertises 4 channels, but two of those channels are the compression mics at the top. Those are great for interviewing people in public where you might want some of the background noise from your location. Normally we use the XLR pluin mic ports at the bottom of the unit. Here are direct links to Amazon for these products.
Equipment upgrade. Our next step was to upgrade our recorder so that we could have everyone on their own channel. This gives us more control on editing, especially when people talk over each other like we tend to do.
Go with free on this one. There is no reason to buy something fancy.